Drive device for a movably mounted furniture part

ABSTRACT

The invention relates to a drive device ( 2 ) for a furniture part ( 7 ) that is displaceably mounted in relation to a furniture body, in particular for a drawer or similar. Said device comprises an energy accumulator device ( 10 ), which supports the displacement of the furniture part ( 7 ). According to the invention, the displaceable furniture part ( 7 ) can be essentially displaced into a fully open position by the energy accumulator device ( 10 )), thus partially discharging the energy accumulator device ( 10 )). The energy accumulator ( 10 ) device is then re-charged during the closing operation of the displaceable furniture part ( 7 ). Said energy accumulator device ( 10 ) only acts on part of the displacement path of the furniture part ( 7 ).

This application is a continuation of International Application No.PCT/AT2005/000448, filed Nov. 10, 2005.

The present invention relates to a drive device for a furniture partwhich is mounted movably relative to a furniture body, particularly fora drawer or the like, having an energy storage device which assists themovement of the furniture part.

The invention also relates to an item of furniture with a furniture partwhich is mounted movably relative to a furniture body, and also to amethod of moving a furniture part of this kind into its open position.

According to the prior art, numerous embodiments of retraction devicesare known, in which an energy storage device conveys the furniture partinto the fully closed position. It is also known to provide suchretraction devices with damping devices, which, if the movable furniturepart is swung shut, at least reduce the banging noises occurringthereby, and thus also reduce the mechanical stress upon the systemcomponents. European Patent EP 0 391 221 by the Applicant describes aclosure device for drawers, in which a displaceable rocker segment isbrought into a stand-by position counter to the force of a spring whenthe drawer is pulled out. When the drawer is pushed in, the rockersegment is disengaged again by virtue of an entrainment member, whereinthe rocker segment is being pulled back into its initial position by aspring. In so doing, the rocker segment entrains the entrainment memberof the drawer, so that the drawer is retracted into its fully closedposition.

It is an object of the present invention to propose a drive device ofthe kind mentioned in the introduction, by means of which the movablefurniture part can be moved into the fully open position, wherein thisoperation is intended to take place as uniform as possible.

According to the invention, this is achieved by virtue of the fact thatthe movable furniture part can be moved essentially into the fully openposition by means of the energy storage device, wherein the energystorage device is at least partly discharged, and, during the closureoperation of the movable furniture part the energy storage device isrechargeable, wherein the energy storage device is only being effectiveover part of the path of movement of the furniture part.

By virtue of the energy storage device of the afore-described kind,temporary coupling of the energy storage device with the movablefurniture part is made possible, so that this latter can be moved intothe fully open position. A movement of the movable furniture part in thedirection of its closed position, starting from the fully open position,causes the energy storage device to be charged, so that a new stand-byposition can be set up. During the opening procedure, the movablefurniture part is initially freely movable until it is moved by means ofa releasable coupling device back further towards the direction of itsfully open position.

The opening of the drawer into the fully open position by means of theinventive drive device is advantageous in several ways. With the openingof short drawers, rebounding can be effectively prevented, in particularif there is damping over the last region of opening of the pull-outpath. Another advantage is the ease of operation and the avoidance ofaccidental self-closure. If removably fitted inserts, or objects, areinside the drawer, which require the drawer to be pulled out fully inorder for them to be removed, the drive device according to theinvention can be used to advantage in such a situation.

A preferred embodiment of the invention provides that the energy storagedevice has a spring device with at least one spring. As a result, thedrive device is simple in its construction and is inexpensive to make.Alternatively, or as an additional measure, the energy storage devicecan also be equipped with at least one pressurised gas storage device.In this case, it can also be advantageous to use the power from anexternal energy source—e.g. an electric motor—to form and/or assist theenergy storage device.

Advantageously, it is provided that the drive device has a rockersegment which is preferably spring-loaded and which can be releasablycoupled to an entrainment member, the entrainment member tensioning thespring by means of the rocker segment during closure of the movablefurniture part, wherein the rocker segment then reaches a stand-byposition which is arrested in self-locking manner, and then releases theentrainment member. The rocking of the rocker segment can thus becontrolled with accuracy, and is not dependent upon the greater orlesser extent to which pull is exerted upon the movable furniture part.

In terms of its construction, the design can be such that the rockersegment is arranged on the furniture body, and the entrainment member isarranged on the movably mounted furniture part. However, the reversesolution also lies within the scope of the invention, namely that therocker segment is arranged on the movably mounted furniture part, andthe entrainment member is arranged on the furniture body.

An advantageous embodiment of the invention results if the rockersegment is preferably guided in displaceable manner linearly along aguide path. The rocker segment can be guided with accuracy along thepath of movement provided for it, thus permitting reliable couplingwhich is free of clearance. The guide path can lie in a rail which isheld by fixing means to the side wall of the furniture body.

As an alternative, the design can be such that the rocker segment ismounted rotatably about an axis, and can be moved into a stand-byposition which is arrested in self-locking manner. This results in aspace-conserving variant in comparison to the rocker segment which isguided in the guide path.

So that the movable furniture part is not brought into the fully openposition with too much momentum, it is advantageously provided that adamping device is provided which dampens the movement of the furniturepart over at least part of its path of opening. The damping device canessentially be based on any solutions known in the prior art, the use oflinear dampers, or even rotary dampers, advantageously being possible.

The arrangement of the damping device can also vary. One embodimentprovides that the damping device is arranged on the movable furniturepart. It can also be advantageous if the damping device is arranged on aguide rail of a pull-out guide fitting. Alternatively, it can also beprovided that the damping device is arranged on the rocker segment.Depending upon the application—e.g. in the case of drawers which arevery heavy, or which are to be loaded so that they will become heavy—acombination of the afore-mentioned damping arrangements is providedwithin the scope of the invention.

Another advantageous embodiment of the invention results if a closuredevice is additionally provided by means of which the movable furniturepart can be moved into its fully closed position. The movable furniturepart can thus be moved within the region of the two end positions of thepath of movement, both into the fully closed position as well as intothe fully open position, gentle and smooth closure and openingoperations being possible into both end positions.

The item of furniture according to the invention with a furniture partwhich is mounted movably relative to a furniture body is characterisedin that it has a drive device of the afore-mentioned kind.

The method according to the invention for moving into its open positiona furniture part which is movably mounted relative to a furniture bodyis characterised in that the movable furniture part is initially freelymovable during the opening operation, then is taken hold of by adetachable coupling device (rocker segment), and is pulled further inthe direction of its open position by an energy storage device, and adamping device provides damping over the last path of opening.

A preferred embodiment of the afore-mentioned method results if thedamping effect of the damping device upon opening of the furniture partonly begins when the detachable coupling device (rocker segment) hascoupled the movable furniture part, or an entrainment member of same, tothe energy storage device. If the movable furniture part, or theentrainment member thereof, is not coupled, then the movable furniturepart could possibly move backwards when travelling onto the dampingdevice, in which case smooth pulling out could not be ensured.

Further details and advantages of the present invention will bementioned hereinafter in greater detail with the aid of the descriptionof the drawings relating to the Figures:

FIGS. 1 a, 1 b, 1 c show the front region of a pull-out guide fittingfor drawers with a drive device according to the invention, and alsodetailed drawings on a larger scale,

FIGS. 2 a, 2 b, 2 c show the chronological sequences of opening thedrawer, according to an alternative embodiment,

FIGS. 3 a, 3 b, 3 c show the embodiment from FIGS. 1 a-1 c with anadditional closure device, and also detailed drawings on a larger scale,

FIGS. 4 a, 4 b show a pull-out guide fitting with a closure device andthe drive device from FIGS. 2 a-2 c in detailed drawings on a largerscale, and

FIGS. 5 a-5 f illustrate the course of the closure operation of a drawerin chronological sequences.

FIG. 1 a shows the front region of a pull-out guide fitting 1 fordrawers with the drive device 2 according to the invention. FIG. 1 b isa view of the detail D in FIG. 1 a, and FIG. 1 c is a sectional drawingtaken along the line A-A of FIG. 1 a. The pull-out guide fitting 1 is inthe open position, the drawer rail 6 being engaged with the drive device2. Other than in respect of the drive device 2, the pull-out guidefitting 1 corresponds to the prior art, i.e. a carcass rail 3 is fixedlyconnected with a furniture body. Between the carcass rail 3 and thedrawer rail 6 there is a central rail 8 which is displaceable relativeto these two rails 3, 6. The load between the rails is transmitted bymeans of rollers, balls or rolls, or conventional carriages, not shown.The drive device 2 is preferably disposed in the front half of thepull-out path of a drawer which is fixedly connected to the drawer rail6. The drive device 2 can be arranged between the side wall of thedrawer and the side wall of the carcass, or it can also be arrangedunder the bottom of the drawer. The drive device 2—as shown in FIG. 1b—comprises an energy storage device 10 in the form of at least one(tension) spring by means of which a drawer can be moved into its fullyopen position. The energy storage device 10 is pivoted to the fixingjournal 11, on the one hand, and communicates via the direction-changingmember 12 with a rocker segment 14. The rocker segment 14 can be of aforked configuration, and is displaceable along a guide path 13 by meansof an engaging journal. The guide path 13 has a straight portion, inboth end regions of which the arcuate portions 13′ and 13″ are arranged.In the drawing shown, an entrainment member 15 makes contact with therocker segment 14. The entrainment member 15 is secured fixedly in therear region of the drawer rail 6, or is formed thereon. However, theentrainment member 15 can also be secured directly to a side wall of thedrawer. If the drawer is then opened, starting from its fully closedposition, then it is possible to move it freely first of all. At thattime, the spring-loaded rocker segment 14 is disposed in the arcuateportion 13″ in a stand-by position which is arrested in a self-lockingway. When the drawer approaches its fully open position, the entrainmentmember 15 is grasped by the rocker segment 14. When this happens, therocker segment 14 is lifted by the entrainment member 15 out of thearcuate portion 13″, and is moved by spring force in the direction ofthe second arcuate portion 13′. In this position, the entrainment member15 is able to be released again from the rocker segment 14, free runningof the entrainment member 15, or of the drawer, being possible. As analternative, the entrainment member 15 can also continue to be connectedto the rocker segment 14, which, of course, simultaneously denotes thefully open position. In order to move the drawer, or the entrainmentmember 15, into the fully open position, it is advantageously providedthat the energy storage device 10 is designed such that it does notbecome fully discharged when the drawer is in the fully open position.This means that in that position the spring(s) is/are at least partlytensioned, so that the rocker segment 14 is tensioned even when thedrawer is fully open.

If the movable furniture part is closed, starting from its fully openposition, then the entrainment member 15 becomes once again coupled tothe rocker segment 14, and the energy storage device 10 becomesrecharged, i.e. the spring is tensioned. When the movable furniture partmoves further in the direction of its closed position, the rockersegment 14 again takes up a stand-by position which is arrested inself-locking manner (rocker segment 14 in the arcuate portion 13′) andreleases the entrainment member 15, so that the drawer can be moved intothe closed position.

FIG. 1 c shows a sectional drawing along the axis A-A in FIG. 1 a. Theposition of the rails 3, 6, 8 relative to one another is visible,wherein for the sake of simplicity no load-transmitting members, such asballs, rolls, or the like, are shown. In order to prevent the drawerfrom reaching the fully open position with a loud banging noise, adamping device 17 is shown here by way of example, which can have atleast one linear damper or rotary damper.

FIGS. 2 a, 2 b, 2 c show chronological sequences of the openingprocedure, according to an alternative embodiment of the invention.Instead of the rocker segment 14 which can be displaced in a linearmanner, as shown in FIGS. 1 a-1 c, a V-shaped rocker segment 14 isprovided which is mounted rotatably about an axis 18. The energy storagedevice 10 comprises a spring which is coupled to the fixing journal 11,on the one hand, and to the rocker segment 14, on the other hand. Theprojecting flap 16 is arranged in the front region of the carcass rail3, and serves to receive the drive device 2. In FIG. 2 a, the rotatablymounted rocker segment 14 is disposed in a stand-by position which isarrested in self-locking manner. This can be done easily by virtue of adetent, or by a lug disposed on the underside of the rocker segment 14which co-operates with a cavity 21 formed in the flap 16, as shown byway of example in FIG. 2 b. FIG. 2 b also shows the entrainment member15 which is already to be found in the engaged condition and which isdisplaced by spring force, to the right, in the direction of the openposition. FIG. 2 c shows the essentially fully open position of thedrawer rail 6 relative to the central rail 5. In the embodiment shown,the entrainment member 15 remains in the section of the V-shaped rockersegment 14, so that no free running of the drawer rail 6 is provided. Ifthe drawer rail 6 is pushed in again, then operation can be completed inthe sequence: FIG. 2 c-2 b-2 a. The energy storage device 10 isrecharged, the spring is thus tensioned, and the rocker segment 14 isreturned to the arrested stand-by position shown in FIG. 2 a.

FIGS. 3 a, 3 b, 3 c show the embodiment from FIGS. 1 a-1 c, wherein inaddition to the drive device 2 a closure device 19 is provided by meansof which the movably mounted furniture part is movable into its fullyclosed position. The closure device 19 corresponds basically to theprior art, and can have a damping device which provides dampening overthe last closure path of the drawer until it is in the fully closedposition. FIG. 3 a shows the detail A from FIG. 1 a, wherein from aconstructional viewpoint the components of the closure device 19correspond to the components of the drive device 2. A rocker segment 14′is guided displaceably along a guide path 13 a. However, in the rearregion the guide path 13 a has a straight section because in this fullyclosed position it is not absolutely necessary for the entrainmentmember 15 to be disengaged. If the drawer is then moved in the directionof its closed position, the entrainment member 15 becomes coupled to therocker segment 14′. The rocker segment 14′ is lifted out of the arrestedstand-by position, and is pulled by spring force into the most rearwardclosed position. FIG. 3 c shows the detail B with the drive device 2,wherein the functional description can be deduced from FIG. 1 b.

FIG. 4 a shows a variant of the embodiment in FIGS. 3 a-3 c, FIG. 4 bshows the view on a large scale of the detail A in FIG. 4 a. In thefront region of the pull-out guide fitting 1 there is a drive device 2with a rotatably mounted rocker segment 14 according to FIGS. 2 a-2 c,whilst the closure device 19 has a displaceably mounted rocker segment14′. By virtue of the closure device 19 and the drive device 2, themovable furniture part can be brought, with damping, into the respectiveend positions of the drawer. Clearly, any possible combination ofrotatably mounted rocker segment 14 and displaceably mounted rockersegment 14′ in closure device 19 and drive device 2 is also possible.

FIGS. 5 a-5 f show schematically the course of a closure operation inchronological sequences. A movably mounted furniture part 7 in the formof a drawer is to be found in the fully open position in FIG. 5 a. Adamping device 17 in the form of a linear damper is disposed in thepushed in state, wherein an abutment 20 on the drawer 7 cooperates witha piston rod of the damping device 17. The closure device 19 which isarranged in the draw-in region, and the drive device 2 on the pull-outside are to be seen, and, in the embodiment shown, are identical indesign apart from the shape of the guide paths 13, 13 a. In FIG. 5 a,the entrainment member 15 is disengaged from the rocker segment 14 ofthe drive device 2. The entrainment member 15 can be fixed or formed onthe drawer 7, the furniture body, or on the pull-out rail, on thedrawer-side, of a pull-out guide fitting. For the sake of simplicity, inFIGS. 5 b-5 f, only some of the reference numerals are shown. However,they correspond to the reference numerals of FIG. 5 a, the samereference numerals denoting like parts. If the drawer 7 is closed (FIG.5 b), the entrainment member 15 is temporarily coupled with the rockersegment 14, so that the energy storage device 10 in form of a spring istensioned. In FIG. 5 c, the rocker segment 14 is disposed in a standbyposition which is arrested in self-locking manner and in which theentrainment member 15 is once again uncoupled. The drawer 7 is thenfreely movable over the region between the drive device 2 and theclosure device 19.

In FIG. 5 b, the rocker segment 14′ of the closure device 19 is disposedin the standby position with tensioned energy storage device 10′. Theentrainment member 15 can engage in the slot of the rocker segment 14′.By virtue of the tensioned spring of the energy storage device 10′ theentrainment member 15 is moved in the direction of its closure position(FIG. 5 e), and is advantageously damped over the final closure path, sothat severe impact in the fully closed position can be avoided. FIG. 5 fshows the drawer 7 fully pushed into the furniture body. The openingoperation can take place in like manner on the basis of FIG. 5 f to FIG.5 a.

The present invention is not limited to the embodiments which have beenshown, but can encompass, or be extended to, any variants and technicalequivalents coming within the scope of the subsequent claims. Theindications pertaining to positions, which have been chosen in thedescription, e.g. above, below, side, etc., relate to the figure shownand described directly, and are to be applied logically to the newposition in the event of a change of position. It will readily beappreciated that the drive device according to the invention can bearranged, not just on one side, but also on both sides of the drawer.This is particularly expedient if large drawers, or drawers which areloaded so that they are heavy, or front pull-out fitments, are to bemoved. The course of movement can therefore be more effective andsmoother, and guidance of the moved furniture part can be positivelyinfluenced thereby.

1. A drive device for a furniture part which is mounted movably relativeto a furniture body, comprising: an energy storage device which assiststhe movement of said furniture part, wherein said movable furniture partcan be moved essentially into the fully open position by means of saidenergy storage device whereby said energy storage device is at leastpartly discharged, and, during the closure operation of said movablefurniture part said energy storage device is rechargeable, wherein saidenergy storage device only being effective over part of the path ofmovement of said furniture part.
 2. The drive device according to claim1, wherein said energy storage device comprises a spring device with atleast one spring.
 3. The drive device according to claim 2, wherein saiddrive unit comprises a rocker segment which is spring-loaded and whichcan be coupled releasably to an entrainment member, said entrainmentmember tensioning said spring by means of said rocker segment duringclosure of said movable furniture part, wherein said rocker segment thenreaches a stand-by position which is arrested in self-locking manner,and then releases said entrainment member.
 4. The drive device accordingto claim 3, wherein said rocker segment is arranged on said furniturebody, and said entrainment member is arranged on said movably mountedfurniture part.
 5. The drive device according to claim 3, wherein saidrocker segment is arranged on said movably mounted furniture part, andsaid entrainment member is arranged on said furniture body.
 6. The drivedevice according to claim 3, wherein said rocker segment is guided in adisplaceable manner linearly along a guide path.
 7. The drive deviceaccording to claim 3, wherein said rocker segment is mounted rotatablyabout an axis, and can be moved into a stand-by position which isarrested in self-locking manner.
 8. The drive device according to claim1, wherein a damping device is provided which dampens the movement ofsaid furniture part over at least part of its path of opening.
 9. Thedrive device according to claim 8, wherein said damping device isarranged on said movable furniture part.
 10. The drive device accordingto claim 8, wherein said damping device is arranged on a guide rail of apull-out guide fitting for drawers.
 11. The drive device according toclaim 8, wherein said damping device is arranged on said rocker segment.12. The drive device according to claim 1, wherein a closure device isadditionally provided by means of which said movable furniture part canbe moved into its fully closed position.
 13. The drive device accordingto claim 1, wherein the movable furniture part is in the form of adrawer.
 14. An item of furniture with a furniture part movably mountedrelative to a furniture body comprising a drive device according toclaim
 1. 15. A method of moving a furniture part which is movablymounted relative to a furniture body into its open position, whereinsaid movable furniture part is initially freely movable during theopening operation, then is taken hold of by a detachable coupling device(rocker segment), and is pulled further in the direction of its openposition by an energy storage device, and is dampened by a dampingdevice over the last path of opening.
 16. The method according to claim14, wherein the damping action of said damping device only begins uponopening of said furniture part, when the detachable coupling device(rocker segment) has coupled said movable furniture part, or anentrainment member of same, to said energy storage device.